From patchwork Thu Jan 12 13:53:50 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 13098136 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5F805C678D6 for ; Thu, 12 Jan 2023 14:34:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239000AbjALOe5 (ORCPT ); Thu, 12 Jan 2023 09:34:57 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55100 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238117AbjALOdy (ORCPT ); Thu, 12 Jan 2023 09:33:54 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 29FC85B17B; Thu, 12 Jan 2023 06:25:48 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id BB1CE61FCB; Thu, 12 Jan 2023 14:25:47 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9838DC433F0; Thu, 12 Jan 2023 14:25:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1673533547; bh=FX7HYEbBIhWrHLNd17fteXtIabssxjGxuMAlpWlubRM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=J7FQI08TDp/R3yqOGmwz2h2dKZELePRX3oqwOcz/TcIsVa0ro2lwrsiW8QxRurplV bX3/1cHX4q8sja03dSXXKANV3WNVtaJocojQqzHRdlbosclCpIcVPi4cwKtpa6Iyt8 ByhlLy3PsPBOaifNylgc/awEiVTgrjpMIbw76MaE= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Rob Clark , Sean Paul , Abhinav Kumar , linux-arm-msm@vger.kernel.org, freedreno@lists.freedesktop.org, Dmitry Baryshkov , Daniel Vetter , =?utf-8?b?VmlsbGUgU3lyasOkbMOk?= , Sasha Levin Subject: [PATCH 5.10 514/783] drm/msm: Use drm_mode_copy() Date: Thu, 12 Jan 2023 14:53:50 +0100 Message-Id: <20230112135548.035594078@linuxfoundation.org> X-Mailer: git-send-email 2.39.0 In-Reply-To: <20230112135524.143670746@linuxfoundation.org> References: <20230112135524.143670746@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org From: Ville Syrjälä [ Upstream commit b2a1c5ca50db22b3677676dd5bad5f6092429acf ] struct drm_display_mode embeds a list head, so overwriting the full struct with another one will corrupt the list (if the destination mode is on a list). Use drm_mode_copy() instead which explicitly preserves the list head of the destination mode. Even if we know the destination mode is not on any list using drm_mode_copy() seems decent as it sets a good example. Bad examples of not using it might eventually get copied into code where preserving the list head actually matters. Obviously one case not covered here is when the mode itself is embedded in a larger structure and the whole structure is copied. But if we are careful when copying into modes embedded in structures I think we can be a little more reassured that bogus list heads haven't been propagated in. @is_mode_copy@ @@ drm_mode_copy(...) { ... } @depends on !is_mode_copy@ struct drm_display_mode *mode; expression E, S; @@ ( - *mode = E + drm_mode_copy(mode, &E) | - memcpy(mode, E, S) + drm_mode_copy(mode, E) ) @depends on !is_mode_copy@ struct drm_display_mode mode; expression E; @@ ( - mode = E + drm_mode_copy(&mode, &E) | - memcpy(&mode, E, S) + drm_mode_copy(&mode, E) ) @@ struct drm_display_mode *mode; @@ - &*mode + mode Cc: Rob Clark Cc: Sean Paul Cc: Abhinav Kumar Cc: linux-arm-msm@vger.kernel.org Cc: freedreno@lists.freedesktop.org Reviewed-by: Dmitry Baryshkov Reviewed-by: Abhinav Kumar Reviewed-by: Daniel Vetter Signed-off-by: Ville Syrjälä Link: https://patchwork.freedesktop.org/patch/msgid/20221107192545.9896-5-ville.syrjala@linux.intel.com Signed-off-by: Sasha Levin --- drivers/gpu/drm/msm/dp/dp_display.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c index 5a152d505dfb..1c3dcbc6cce8 100644 --- a/drivers/gpu/drm/msm/dp/dp_display.c +++ b/drivers/gpu/drm/msm/dp/dp_display.c @@ -848,7 +848,7 @@ static int dp_display_set_mode(struct msm_dp *dp_display, dp = container_of(dp_display, struct dp_display_private, dp_display); - dp->panel->dp_mode.drm_mode = mode->drm_mode; + drm_mode_copy(&dp->panel->dp_mode.drm_mode, &mode->drm_mode); dp->panel->dp_mode.bpp = mode->bpp; dp->panel->dp_mode.capabilities = mode->capabilities; dp_panel_init_panel_info(dp->panel);